Field of the Invention
The present invention relates to a method for providing a mixed reality in which an image of a real space is displayed with a virtual object superimposed thereon.
Description of the Related Art
A mixed reality (MR) technique and an augmented reality (AR) technique are known as techniques for merging a real world with a virtual world in real time. These techniques seamlessly merge a real space with a virtual space created by a computer. It is expected that these techniques are applied to a variety of fields including an assembly support in which operation procedures and wiring conditions are superimposed on a display during an assembly operation and a construction simulation in which the interior and the exterior of a building are checked prior to the actual construction through computer graphics (CG) superimposed on a display.
Apparatuses that allow a user to sense a virtual object as if the virtual object is present in a real space includes a head-mounted display (HMD). In particular, a video see-through HMD captures an image of a real world with a mounted video camera and displays a composite image obtained by superimposing a virtual object on the captured image in real time on a display unit such as a display to thus present the composite image to the user.
When a display unit with a strong sense of immersion such as an HMD is used, there is a possibility that a user among a plurality of users experiencing the MR does not notice another user approaching him or her and comes very close to the another user. Thus, Japanese Patent Application Laid-Open No. 2006-301924 discusses a method in which a viewpoint position and its direction of a first user and a viewpoint position and its direction of a second user are obtained and the first user is notified of the second user approaching the first user when the distance between the first and second users falls below a threshold value.
However, the method discussed in Japanese Patent Application Laid-Open No. 2006-301924 has shortcomings in that a user cannot be notified of a real object, such as a table and a wall, present in the real space that the user is approaching since the method is directed to notifying the user of another user approaching him or her.